I've got a pair of $30 Igogs i bought for a fishing trip 3 years ago that are still going strong. They've been tossed around tractor/combine cabs, my truck, kids messing with them, etc. Plus they are comfortable as can be on my giant gourd. For the cost Oakley's better give me Xray vision or something because my cheap glasses give me all the benefits that Oakley wearers talk about. And before anyone asks yes I have tried on Oakleys, didn't see what was worth the extra cost.
The only expensive glasses I ever contemplated buying were a pair of Costa Del Mar's. Still didn't see how the extra cost was worth it.